Vehicole actuated traffic controller



y 1950 v. LEONARD I 2,506,368

VEHICLE ACTUATED TRAFFIC CONTROLLER Filed Dec. 24, 1946 3 Sheets-Sheet lPigJA l0 /4 I r E000 Inventor: VincenbWLeonard,

His Attorney.

May 2, 1950 v. w. LEONARD VEHICLE ACTUATED TRAFFIC CONTROLLER 5Sheets-Sheet 2 Filed Dec. 24, 1946 h u M a 2 n P u 6 M I F =R 8 4 q M wm 325? W J Jbh 56 4 T 8 7 7 M W M Q 1- x a x m a E M M ,mwl m w w w 1 a2 My m M u w i 7 8 w w n M 9 8 I 0% 7 9 w I I nventor: Vincent WLeonard,y

WWPZZT? His Attorney.

May 2, 1950 v W II EQNARD 2,506,368

VEHICLE ACTUATED TRAFFIC CONTROLLER Filed Dec. 24, 1946 3 Sheets-Sheet 3Inventor: VincentWLeonard,

His Attorney.

Patented May 2, 1959 2,506,368 VEHICLE ACTUATED TRAFFIC CONTROLLERVincent W. Leonard,

General New York Electric Com Saugus, Mass, assignor to pany, acorporation of Application liecember 24, 1946, Serial No. 718,180

28 Claims.

My invention relates to traflic signal control systems, and moreparticularly to vehicle actuated trafiic signal control systems andapparatus therefor.

It is a general object of my invention to provide a new and improvedvehicle actuated traffic signal control system.

It is a further object of the invention to provide a, vehicle actuatedtraific signal control apparatus which is manually adjustable to providea plurality of selectable modes of operation.

It is a still further object of the invention to provide a vehicleactuated traffic signal control apparatus comprising a rotatable signalprogram controller having a plurality of positions of rest correspondingto predetermined conditions of signal indication, and means responsiveto the approach of a vehicle for permitting intermittent movement ofsaid controller between said positions to alternate, maintain and extendthe vari- \O'HS sign-a1 indications.

It is another object of my invention to provide a vehicle actuatedtraffic signal control apparatus comprising a rotatable signal programcontroller including electric braking means, and detector means forcontrolling the braking means to permit intermittent rotation of thecontroller in accordance with vehicle actuation.

,Another object of my invention is the provision of a vehicle actuatedtraflic signal control system comprising a rotatable signal programcontroller having positions of rest corresponding to a right-of-wayindication on each controlled :t'raffic lane, in combination with newand novel means responsive to approaching vehicles for intermittentlyreleasing said controller for movement between said positions inaccordance with trafic conditions.

A further object of the invention is the provision of a rotatable signalprogram controller arranged for normal continuous rotation, incombination with new and novel means for intermittently stoppingrotation of the controller in response to vehicle actuation.

It is still another object of the invention to provide a vehicleactuated trafiic signal control apparatus which, by simple switchingadjustment, may be made to operate either as a pretimed controller withright-of-way extension by vehicles approaching a go signal, or as a fullactuated controller with the go signal remaining upon the trafilc lanelast called, or as a full actuated controller with the go signalnormally returning to and remaining on any selected lane in the absenceof actuation, or as a part-ac 2 tuated controller with or without recallto the street having the detector, or as a manually operated controller.

Another object of the invention is the provision of a new and novelvehicle actuated trafiic signal control apparatus comprising a rotatablesignal program controller of the pro-timed type normally intermittentlyoperated in response to the approach of vehicles and provided withseparate electronic interval timing apparatus removable as a unitwithout interfering with the ability of the program controller tooperate continuously as a pre-timed controller.

My invention will be more fully understood and its various Objects andadvantages further appreciated by referring now to the illustrativeembodiment described in the following detailed specification andaccompanying drawings, in which Figs. 1A and 1B, taken together as Fig.1,

show a schematic circuit diagram of a vehicle actuated traific signalcontrol system embodying my invention; and Figs. 2 to 8, inclusive, aresimplified circuit diagrams of certain of the individual circuits shownat Figs. 1A and 13.

Referring now to the drawings, and particularly to Figs. 1, I have showntherein a vehicle actuated trafiic signal control system comprising a,signal device it of the type comprising a red, amber and greenindicating light for each intersecting traffic lane, a, trafiic signalprogram controller I I for controlling the signal device iii, anelectronic interval timing unit I? (Fig. 1B) and a plurality of vehicleactuable detector units l3a, I31), I30 and 53d, one pair for each of twointersecting traific lanes M and C. While my invention is equallyapplicable to the control of multiple intersections of three or morelanes or streets, I have shown by way of illustration only an embodimentarranged to control a single pair of intersecting streets M and C. Thestreet M may be regarded as a main thoroughfare and the street C as across street.

The interval timing unit of Fig. 1B connects to the controller of Fig.1A by a single plug connector I211. The two figures fit together simplyby superposing the connector Hit of Fig. 113 on the connector |2a ofFig. 1A, the aligned vertical and horizontal wires on opposite sides ofthe plug being then respectively connected within the plug.

The signal program controller H is generally similar in construction tothat described and claimed in Patents 2,236,297 2,236,298 and 2,235,-299 issued to Ralph A. Reid on March 25, 1941. Briefly, this controllercomprises a rotatable timsolenoid is co fully hereinafter.

as ing dial i i and a signal drum Him. The timing dial Hi is driven by asynchronous timing motor having an armature Hi and a pair of mutuallyopposed field exciting windings ill and it. motor operation the held itonly is energized. When it is desired to stop the motor the opposingwinding 57 is also energized, so that the field winding i? will bereferred to hereinafter as the braking field or braking coil. The timingdial it is provided with two concentric rows of radial slots iiiand M.In the slots is and 28 are positinned a. plurality of contact actuatingkeys 2%, 22, 23 and 2% arranged to cooperate with a plurality of pairsof dial contacts Zia, 22a, 23a and 25a, respectively. The dial contactsare mount ed upon the controller base (not shown) adjacent timing dialM.

All. the dial contacts Zia, to l la, inclusive, are normally open andare closed only when engaged by one of the actuating keys in the dial.The contacts Zia are recurrently closed by the keys 2i in the outer rowof slots it of the timing dial. The contacts 22a are closed once perrevolution 'per cycle of the timing dial is by the key 22 positioned inthe outer row of slots but apertured to avoid engagement with thecontacts am. The contacts 23a are closed once per cycle by the key 25 inthe inner row of slots of the timing dial, while the contacts 2 m areclosed once per cycle of the dial it by the longer key positioned in theinner row of slots and apertured to avoiden'g'agementwith the contacts25a. Ihe motor shaft also carries a toothed cam 25 arranged recurr'entlyto actuate a pair of flasher contacts .26. The contacts '22 operate inconjunction with a manual transfer switch '21 to produce continuous"lashing operation of the amber lamps in the signal device it wheneverthe switch 2? is manually set for such operation.

In the position shown the switch 21 is set for sequential red, amber andgreen signal indication.

Thesignaldrurn comprises'a rotatable cam shaft 2% carrying a pluralityof cams 2% to G2 inclusive, and is advancedintermittently through a pawland ratchet' ifi lit by a solenoid Q5. The

"nt'rolle'd by the dial contacts 2m and 22a associated with the timingdial it. The drum cams estate, inclusive, control a plurality of drumcontacts "t0'59, respectively. 'The to Eficontrol'the sequence of signallamp energiaation. The drum contacts 51,

5?. and are provided as spares for any special use which may be desired,and the remaining drum contacts 52- drum contacts are connected asinterlock contacts in the control system to be described more Asmentioned above, the. solenoid as is conrolled by the dial contacts tlu,and 22a. These contacts are actuated by keys 2i and 22 in the outer rowoi' slots inthe dial it. in the embodiment of the invention shownthedrum controller tea has six positions. Thus, in order that one completerevolution of the." dial It. shall produce one complete revolution orcycle of the drum Ma,

there must be six keys in the outer row of slots.

it may be thatthe signal sequence'selected does not require keys. Inthis case, some of the keys must be used as dummy" keys in the sensethat they advance the drum i l-a even though the drum cams are so shapedas to effect no change in signal energiaation' upon such dummy advance.

To maintain a synchronous relation between the program timing. dial itand the drum Ida, one ofthe drum contactsiis included in thenormueaeraahg circuit of the drum advance sole-" noid it. The drumcontact 46 associated with the drum cam 29 is arranged to be closed inall except one position of the drum shaft 28 and is connected in seriescircuit relation with the normal energizing circuit for the solenoid $5.This normal energizing circuit may be followed from the high potentialline L of a suitable source of alternating current supply through thenormally open dial contacts Zia, the drum interlock con tact it, amanually operable selector switch 60 and an actuating winding iii of thesolenoid 45 to ground. The alternating current supply source isconnected by conductors N and I.- to a terminal board T, the conductor Nbeing grounded. Thus, in the due drumshaft position in which theinterlock contact is open the drum advance keys 2| on the timing dial itare unable to energize the solenoid 35. In this position of the drumshaft an alternative solenoid energizing circuit is completed throughthe dial contact 22a when the contact 22a is actuated by the dial key22. This alternative circuit may be followed from the supply through amanually operable control switch a pair of contacts 21a on the transferswitch 2'5, which are closed except in flashing amber operation of thecontroller, the dial contacts 22a, the manually operable selector switch6i? and the actuating winding G! of the solenoid as. The-selector switch6i! is shown in position for automatic operation, but is shown providedalso with an alternative position which disconnects solenoid as from thetiming dial it and connects the-solenoid for manual'drum advancingoperation by a push button 6-3.

For flashing amber operation the transfer switch is provided wane pairof contacts 211) and c which,iwhenengaged, connect the amber lamps ofthe signal device it in parallel circuit relation to the supply sourceN, L through the flasher contacts 2 3. Inthis alternative position ofthe transfer switch '2'? the red and green lamp circuits aredisconnected from the supply source at the contacts Zia-of the switch.

In automatic operation the forward field winding it of the timing dialdriving motor i5 is constantly energized througha manually operablecontrol-switched. In the absence of-- vehicle actuation the "timingmotor i5 is normally disabled w the brake coil l1, an 'energizingcircuit for which is-completedeither by the dial contact 23a or by thedial contact 2401.. Since the dial contacts 2 5a and E ic-are controlledby the keys '23 and 2d respectively on the program timing dial ititselflthe brake-coil ll normally holds the a, dial l4 stationary atone-or the other of two positions determined by the positions of thekeys 23 and 24. These keys are located in-the inner row of slots 28 ofthe dial is immediately before the end of the green orright-of-wayperiods on the main and cross streets M and C. The brake coiltir'ning'unitv l2 (Fig. 1B).

The detectOrs'lSa. l3b,'l3c,;and we are connected to the controllerthrough the terminal board T, as indicated in Fig. 1A. These detectorsmay be of anywell'known type which operate to give anelectric impulseupon; the passage of a vehicle. "At-Fig. l, the pairs of detectors i311,l3b, I30 and I301 are shown connected to a pair of relays $7 and iiathrough a pair of detector amplifiers 69'and Efiflrespectively.The'termi-nal board T also provides-three terminals for alterasoascsnative connection to a set of detectors 70 of a type not requiringamplification and relaying.

The brake coil circuit for the program controller timing motor I isshown in simplified form at Fig. 2. The power for the brake coil circuitis taken from the alternating current supply terminals N and L. The coilshown between these terminals at Fig. 2 is the primary winding of anauto transformer ll, shown at Fig. 1B and connected to the power supplyterminals N and L on the terminal board T through the plug connectorI211. At Fig. 2 the brake coil I7 is shown connected to the power supplyterminals N and L through a number of relay and interlock contactsconnected in various combinations of series and parallel circuitrelation. Two alternative brake coil circuits are shown connected inparallel circuit relation through the dial contacts 23a and 24a,respectively. It will be understood that the contacts 23a and 24a arealternately closed, the contacts 23a being closed near the end of the Mstreet green period and the contacts Eda being closed near the end ofthe C street green period, as indicated by the position of the keys 23and 24 on the timing dial I4.

Th dial contacts 23a are connected in the brake coil circuit in seriescircuit relation with a pair of normally closed contacts 13 of aninterval extension relay 14 (Fig. 1A), a pair of normally closedcontacts 15 of a maximum interval timing relay 16 (Fig. 1B), and thedrum contacts 5i] controlled by the drum shaft 28 of the drum controllerMa. The drum contacts 50 are arranged to be closed during the M streetgreen period and open at all other times. The relay contacts 23 and 15are arranged to be shunted by a circuit including in series the recallswitch 65 and a pair of normally closed contacts ll of a memory relay [8(Fig. 1A).

Similarly an anternative brake coil circuit through the dial contacts240. includes in series circuit relation a pair of normally closedcontacts 79 of an interval extension relay 80 (Fig. 1A), a pair ofnormally closed contacts Bl of a maximum interval timing relay 82 (Fig.1B), and the drum contacts 49 on the drum controller Ma. The drumcontacts 49 are arranged to be closed during the C street green intervaland open at all other times. Similarly, also, the relay contacts l9 andBI through a circuit including in series the recall switch -55 and apair of normally closed contacts 83 of a memory relay 84 (Fig. 1A).

The brake coil circuit of Fig. 2 is controlled by the vehicle detectorsl3 through the memory relays i3 and 34 and also through the variousinterval extension and maximum interval relays 74, 16, 8B and 32, theinterval timing relays in turn being controlled by electronic timing circuits shown at Fig. 1B and in simplified form in Figs. 3 and 4.

Referring first to the detector relay circuits shown in simplified format Fig. 5, it will be observed that th normally open relays 6! and 68(Fig. 1A) are arranged alternatively to energize the actuating windings85 and 86 of a pair of de tector relays 8? and 88, respectively. Thedetector relay windings 85 and B6 are supplied with uni-directionalpotential derived from across a portion of a load resistor 89 connectedin a rectifier circuit between the alternating current supply terminalsN and L. This circuit, as shown at Figs. 13 and 5, comprises a pair ofdiode rectifier-s 90 and 9| connected in parallel circuit relation Witheach other and in series with the load reare arranged to be shuntedsistor 89 across the alternating current terminals N and L. That portionof the load resistor 89 from which the detector relay potential is takenis shunted by a high frequency by-pass capacitor 92. The detector relayactuating windings and 86 are shunted by capacitors 93 and 94,respectively, to provide for delayed drop-out of these relays.

At Fig. 8 I have shown an alternative detector relay circuit wherein theactuating windings 85 and 86 of the detector relays are controlleddirectly by the street detectors l9 rather than by the detectors l3through the amplifier relays 61 and 68. It will be understood that thecircuit at Fig. 8 is only used where the street detectors 10 are of adesign which is capable of directly closing control contacts in thedetector relay circuit.

Each detector relay 87, 88 is provided with a pair of normally open anda pair of normally closed contacts. The C street relay 8? includesnormally closed contacts S5 and normally open contacts 26, while the Mstreet relay 88 includes normally closed contacts 9? and normally opencontacts es. The normally open detector relay contacts 95 and 98 controlthe memory relays l8 and 84, respectively, and the normally closed.detector contacts control the electronic extension interval timingcircuits which will be more fully described hereinafter.

The memory relay circuits are shown in simplified form in Fig. 6. Asshown at Fig. 6, the memory relay i8 is provided with an actuatedwinding 9d arranged to be connected across the alternating currentsupply conductors N-L through the drum contacts 41 in series circuitrelation with the normally open detector relay contacts 96. The detectorrelay contacts 96 are arranged to be shunted by a normally openinterlock contact iiiil on the memory relay 78 or by a normally opencontact I 0| on a locking relay It? in series circuit relation with anormally closed contact ilila on the extension relay iii] (Figs. 1A and6). Similarly the memory relay 84 is provided with an actuating windinglee arranged to be connected across the alternating current supplyconductors N-L through the drum contacts 48 in series circuit relationwith the normally open detector relay contacts The detector relaycontacts 98 are arranged to be shunted by a normally open contact ltd onthe memory relay 84 or by a normally open contact 55523 of a lockingrelay M6 in series circuit relation with a normally closed contact 555aon the extension relay 1d. The drum contacts 5'! are arranged to beclosed at all times except during the C street green interval. The drumcontacts as are arranged to be closed at all times except during the Mstreet green interval.

From Fig. 6 it will also be evident that the actuating windings l 01 andIDS of the locking relays Hi2 and M36 respectively, are arranged to beconnected to the alternating current supplyconductors N-L through thedrum contacts 555 and 53, respectively. These drum contacts 55 and 56are those controlling the amber lights on the signal device it). Thecontacts 55 are arranged to be closed only during the amber periodpreceding C street green, and the drum contacts as are arranged to beclosed only during the amber period immediately preceding M streetgreen.

At Fig. 7 I have shown in simplified form the energizing circuits forthe actuating windings Hi9 and H8 of the interval extension relays '14and so, respectively. The actuating winding H39 is arranged to beconnected across the alternating :between the cathode 125 of th reasescurrent'su'pply. conductors N-L. through anormally-open contact III ofan extensionjinterval timing relay Ella which is itself provided with anactuating winding H2 (Fig. 1B). "Similarly, the. actuating'winding [10 fthe interval extension relay '35 is arranged to, be connected across thealternating current supply source through- -,a normally open contact I53 of an extension interval timing relay 3a which is itself providedwith an actuating winding J M (Fig. 1B), The relay windings H2 and H4,are. shunted by capacitors Mia and li la, respectively, for delayeddrop-out operation. 7

The control circuits iorit'he extension interval timing relays Mia andH.301. and the maximum interval timing relays l6 ,and $2 are, shown atFig. 1B and in simplified .form at Figs. 3 and f1. Fig. 3 shows thecircuits ,controllingM street extension .and maximum right-of-wayintervals and Fig. ishows the circuits cont extension and maximumright-of-vvay intervals. The time delay circuits for 0 street and for Mstreet are similar in all respects, so that only Fig. '3 need hedescribed in detail.

eferring then to Fig. 3., the actuating windin ii 52 of the extensioninterval timing relay} ii is connected in the anode circuit of anelectron discharge device ME having an anode lit, a cathode ill, and acontrol electrode are. ihe electron discharge device ME is energizedfrom the autotransformer, H. Specifically, the anode HE isconnectedthrough the time delay relay winding M2 to the terminal-L1 ofthe autotransformer and the cathodeil'l'i isconnected through vthenormally closed Mstreet detector relay contact El to the transformerterminal L. ar cathode ii? is connected :also to the groundedtransformer terminal N through .aresistor H9. Between the transformerterminals N and L there is connected'a voltagedividerplw, and from anintermediate pointcon the voltage divider connection is made .to the:control electrode H8 through a capacitor i2! .andJa discharge resistor522. Thevoltage divider tap is preferably closer electrically to thetransformer =terminal L than to the terminal N.

The M street maximum interval timing relay is is prov ded withanactuating winding {23 connected in the anode circuit of a threeelement.elec ron discharge device MM having an anode 2 5, a cathode E25, andacontrol electrode 525. The electron discharge devicelvlM and the relay:winding #23 are connected to the autotransformcr "i! in a mannerentirely similar to'theconnection of the electrondischarge device ME andthe relay winding H3, except that the connection e discharge device MMand the. transformer terminal Lis through the drum contacts te'which-areclosed only dur- 1. .The cathode:i-25

ougha resistorill, and the control electrode is is connected toaninterrnediate point of a v divider through acapacitor lzg'which isshunted bya discharge. resistor l-Sil. The voltage divider 523isjconncctcd'betwcen the transformer terminals 'L-.and1N.

From r it -will be observed that the actuating winding il of-theextension interval timrelay l li o, is connected in the anode circuit of-a three element electron discharge device CE, and :thatthe cathode ofthe -discharge-de ice CE. is Ec'onnectedztotheiterminalfL of thetransformer 11! through the. normallyjclosed contacts95 'ofthedetector-relay 8?. 'fllhe. cathode pfithe dischar rolling C street d vce CE i c nn ed l o o t e t o mer terminal N through a resistor I 3 I,and the control electrode of the discharge device CE is connected to anintermediate point of a voltage divider 132 through a capacitor I33shunted by adischarge resistor i3 similarly, t e C t e t m m intervaltiming relay 82 is provided with an actuating Winding 135 connected inthe anode circuit or a three-element electron discharge device CM. Thecathode of the discharge device CM is 0011-. nected to the transformerterminal L through the drum contacts is which are closed only during theC street green interval, and is connected also to the'transformerterminal N through a resistor I35. The control electrode of thedischarge deviceCM is connected to an intermediate point on a voltagedivider i fl through a capacitor I38 and a discharge resistor H9 inparallel therewith.

Referring now more particularly to Fig. 3, the operationqof theextension and maximum interval timin circuits will be understood fromthe following brief description. In the extension timcircuit includingthe discharge device ME. it will he pbserved that, in the absence ofvehicle actuation, the detector relay contacts 91 are closed, so thatthe full autotransf ormer voltage applied between the anode and cathodeof the discharge device ME, while a small in phase positive bias isapplied to the control electrode H8 from the voltage divider I20. Thedischarge device ME, therefore, is conductive on alternate half cycles,and the currentthrough thedischarge device maintains the timing relay 1I la picked-up. During negative half cycles when the discharge device MEis not conductive the capacitor H211 discharges through the coil H2 andthus maintains the relay 5 i la picked-up. If now a vehicle crosses anlvl' street detector 311 or 5321, the'amplifier relay 58 (Fig. 1A) ismomentarily picked-up and completes the direct current energizingcircuit for the detector relay 8% (Fig. 13). While actuation of thedetector itself and the relay 68 is only momentarily, the detector r lay88 remains picked-up for a longer time by reason of 3 the capacitor $4shunted across the relay energizing winding as. The capacitor Gd, bydischarging throughthe Winding 85, delays drop-out of the detector relay8 8. Thus upon each Vehicle actuation the contacts 9'5 (Fig. 3)are-opened for u ;an appreciable interval.

When the contacts 91 are opened the plate voltage on the dischargedevice is reduced to one-half its former value because the cathode I llis-now connected to the transformer mid-point N a .through the resistorH9, rather than directly to theline terminal Lasbefore. -Moreover, withthe contacts open an in phase negative-alternating potential is appliedto the control electrode I 8 through the voltage divider EZG and theresistor 1 22. Thedischarge device t .erefore becomes nonccnductiveimmediately upon opening of the contactsei, so that the timing relay llla drops on While the contacts 9! remainopen by reason ,of the delayeddrop-out of the detector relayBB,

the'capacitor 12! in the control electrode circuit of the'dischargedevice ME is charged on'alternate .half cycles through a rectifiercircuit-including the resistor! is andthe cathode-and control elec-.trode or the discharge device ME. Thecharging potential is thatappearing between-the-inter- -mediate tap'on the voltage divider 52s andthe 1tISJKSfOlfi'lelftfillllillal N. By reason of; this charg- ;-ing.-of the capacitor iii the control electrode 8 7 is brought to;arelatively;high negative D. 0,90-

tential with respect to the opposite end of the resistor I22. When nowthe contacts 8? are reclosed upon delayed drop-out of the detector relay38, conduction through the discharge device ME is delayed by thenegative potential thus built up on the control electrode H8. Uponreclosure of the contacts 97, however, the small alternating potentialsupplied between the control electrode and cathode from the lower end ofthe voltage divider 126 is insufficient to maintain the large negativecharge upon the control electrode, so that the capacitor l2l dischargesthrough the resistor I22. When the charge on the capacitor lZl hasleaked off sufiiciently to permit the discharge device ME to conduct,the timing relay llia is again energized by anode cur rent through thedischarge device.

Operation of the maximum timing circuit shown at Fig.3 and including thedischarge device MM is entirely similar to the circuit of the dischargedevice ME, except that the timin is controlled by the drum contacts trather than by a detector relay contact. It will be recalled that thedrum contacts 5! are closed only during the M street green interval.When the contacts 5!! are open the discharge device MM is not conductiveand the maximum timing relay ?5 is dropped out. As soon as the M streetgreen interval begins the contact 50 is closed to initiate time delaypick-up of the timing relay it as determined by discharge of thecapacitor 529. Preferably, of course, the maximum tim ng circuitprovides a longer delay than the extension timing so that the resistorI38 is preferably several times as large as the resistor I22.

The timing circuits shown at Fig. 4 for the cross street C are entirelysimilar to those shown at Fig. 3 for the main street M, and theiroperation will be fully understood from the foreing description. Itshould be noted at Fig. 4 that the circuit of the discharge device CEtimes extension intervals for the cross street, while the circuit of thedischarge device CM times the maximum intervals for the cross street.

With the parts of my improved traffic control system and the apparatusincluded therein, the operation of the system as a whole may now beunderstood. As previously pointed out, the apparatus may be set tooperate in any of a plurality of ways. The various modes of operation ofthe system as determined by the various settings of the apparatus maybest be understood by separate consideration.

FuZZ actuation-Right-of-way street Zast called remaining For operationof the system as a fully actuated system, that is, one in whichdetectors are provided in both the main and the cross streets withprovision for maintenance of right-of-way upon the street last called,both the manually operable recall switches 65 and 66 are closed.Assuming that the conductors N and L on the terminal board T areconnected to a suitable foregoing description of the various out Let itfurther be assumed that no vehicle actuation has occurred during aperiod in excess of any timing interval provided for in the apparatusand that the last vehicle actuation occurred on M street. Under thesecircumstances the dial key 23 will be in position under the dialcontacts 23a, as shown at Fig. 1, thereby to close these contacts and tocomplete a braking circuit for the motor l5 through the braking coil H.The timing dial [4 thus remains at rest in this position. Referring nowto Fig. 2, the assumed braking circuit may be followed from thetransformer terminal N through the brake coil ii, the dial contacts 23a,the recall switch 65, the normally closed memory relay contacts l1, andthe drum contacts as to the transformer terminal L.

Under the conditions assumed, that is, with the timing dial l4 heldstationary near the end of the main street green interval by the dialkey 23, it will be observed from Figs. 3 and 4 that both the main andcross street extension timing relays I Ha and Him are picked-up becausethe detector relay contacts 9'! and 25, respectively, are closed. Also,the main street maximum timing relay '!6 is picked-up because the drumcontacts 5! are closed. However, the cross street maximum timing relay82 is dropped out because the drum contacts 49 are open. Thus in thebrake coil circuit of Fig. 2 the maximum time relay contacts are open,while the main street extension relay contacts 73. are also open byreason of the energization of the extension interval relay M through theextension interval timing relay Illa.

Let it now be assumed that a vehicle actuates one of the 0 streetdetectors l3a or No. An impulse from either of these detectors isamplifled in the amplifier B9 and used to ener ize the relay 5'! (Figs.1A and 5). The relay ii! then picks-up and completes an energizingcircuit for the detector relay 8?. When the detector relay 8'! picks-upit completes, through its normally open contacts 96, an energizingcircuit for the memory relay 18. This energizing circuit is completedthrough the drum contacts l? which are closed in the main street greenposition of the cam drum Ma... When the memory relay l8 picks-up itlocks itself in through its normally open interlock contacts ltd opensits normally closed contacts Ti. When the contacts 1! are opened (Fig.2) the brake coil circuit is interrupted because, as previously pointedout, the timing relay contacts 13 and '!5 are also open. Thus the timingdial M is set in operation to initiate an alternation of the signalindication. As soon as the dial moves the key 23 away from the dialcontacts 23a, both dial contacts 23a, and 24a are open, so that thebrake coil i'l cannot a ain be energized at least for a half revolutionof the dial when the dial key 2 closes the dial contacts 2 4a. As thetiming dial 14 rotates, the dial contacts 21s are recurrently closed bythe dial keys 2!, thereby to effect an intermittent rotation of the drumshaft 28 and to change the signal indication from green on the M streetto greenon C street. As soon as the drum Md arrives at the C streetgreen position the drum contacts 4'! are opened and the memory relay 1%thus deenergized.

If no further vehicle actuation occurs, the timing dial will again cometo rest as soon as the dial key 24 closes the dial contacts 24a, therebyto complete a braking circuit (Fig. 2) through the dial contacts 24a,the recall switch 66, the norand .83(Fig..2):. This istrue because the C11 V V mally closed main street detector relay contacts 83, and the drumcontacts 49, the contacts 49 being closed throughout the C street greenillterval. Since the dial key 24 is located shortly beforethetermination of the C street greeninterval,,the timing dial M willcome to rest with the right-of-way remaining on C street.

During the foregoing operation various timing circuits were set inoperation in a manner which may now be noted. In the first place, assoon as the street detector actuated, and the detector relay 81picked-up, the C street extension interval timing circuit including thedischarge device CE (Fig.4) Was set in operation. When the detectorrelay contacts 95 were opened, the discharge device CE was cut. off andthe relays 113a and fliidropped out. Upon reclosure of the contacts 95by delayed drop-out of the detector relay 8'I,the resistor i3 and thecapacitor iii-3 timed a single extension interval before reenergizationof the timing relay Nita. This extension interval, however, isconsiderably shorter than the C street green interval determinedby thetiming dial M, so that before the dial l4 again comes to rest the timingrelay l l3a-is againenergized and picks-up its interval extension relay8! Similarly, as soon as the C street green interval was initiated thedrumcontacts 49 were closed thereby to initiate timing of a maximumright-ofway interval for C street. This maximuminterval normally isgreater than the C street green interval determined by the timing dialit, so that the maximum interval timing relay 82 will pick-up after thetiming dial comes to rest near the end of C street green. Pick-up of.the timing relay 82, however, has no immediate effect in the absence offurthervehicle. actuation, since it simplyopens its contacts Bl inthebrake coil circuit (Fig. 2-) without interrupting the new brakecoilcircuit through the contacts 66. andlilii.

Let it be assumed for the purpose ofillus- .tration that. the C streetgreen interval determined by the dial I4. is 20 seconds, the. C streetmaximum right-of-way interval determined by the-timing relay 32 is40.seconds,,and the C street extension intervalidetermined by the relay3a is-5 seconds.

It will now be observed that if, after the 0 street vehicle actuationdescribed above, a second vehicle actuation occurs on-C street, thedetector 'relay 8'! will againbepicked. up to. initiate .at its contacts85- a second timing interval for the extensiontiming relay .1 ita.Drop-out of the timing relay i i for one complete extension interval,assumed as 5 seconds, deenergizesthe intervalextension relay 8fl forthe-same length of time. Thus each vehicle'actuation on-C street. duringthe C street greenintervalcausesdrop-out of the extension relay as andclosure of the relay contacts 19 in the: brake. coil circuit for onecomplete extension :interval following such actuation.

If the foregoing second vehicle actuation on .C street i. e., during theC street greeninterval,

occurred more than one. complete extensioninterval (i. e.,-5-seconds)prior to'closure of, the dial contacts-2 3a, the extension timing .has.no eflect, forthe relay contacts T9 are restored to open positionbeforethe contactsl l'a, are closed. If, however, timing ofan extensionintervalis begun less than one such interval before closure of thedialcontacts 24a, closure. of thedial contacts completes a braking circuit.through the relay conof the contacts 65 street maximum timing relay 82has not yet picked-up,

tacts 19 and 8 l independently rest on the .dial key 23 12 so that itscontacts 8| are still closed. It may now be understood that the dial I4is thus held at rest on the key 24 by the extension relay until at least5 seconds after the extending actuation, even though a vehicle actuationon M street causes opening of the memory relay contacts 83.

Similarly, if an additional vehicle actuation occurs on Cstreet prior tothe expiration of the first extension and also prior to the expirationof the maximum interval, the brake coil circuit is maintained for anadditional extension interval (i. e., 5 seconds) from the time of thesecond extending actuation. This action may take place repeatedly,either until the expiration of the last extension called for or untilthe expiration of the maximum timing interval. In the event the lastextension expires without an additional call, the contacts 19 in thebrake coil circuit are opened by the extension timing relay l l3a andthe interval extension relay 80.

When themaximum time interval expires the contacts ill in the brakecoilcircuit are opened by the maximum timing relay 82 so that furtherextensions cannot maintain the brake circuit through thecontacts 19. Ifat the expiration of such maximum time or the expiration of the last Cstreet extension called, no vehicle actuation has occurred on M street,the brake coil circuit remains completed through the recall switch 66and the memory relay contacts- 83, so that the timing dial l remains atrest on the key 24 to maintain the right-of-way indication on C street.If, however, prior to expiration of either of the above timing intervalsa vehicle actuation has occurred on M street, the memory relayv 84 willhave been picked up by the detector relay 88 landlocked in by, itsowncontacts 104. Thus, upon expiration of either or both of the timingintervals mentioned above the brake coil circuit will again beinterrupted and the timing dial it Fullyactuated-With. automatic returnto main street green In order to set the apparatus for automatic returnto M street green, following 0' street rightof-way and without a vehicleactuation on M street, the recall switch 66 is, opened, the recallswitch 65 being left closed. If now it is assumed, as above, thatinitially the timing dial [4 is at near-the end of M street greeninterval, a vehicle actuation on C street will effect a transfer of theright-of-way in the same manner as describedabove, i. e., .by openingthe memory relay contacts 1:1 in the brake coil circuit and releasingthe timing dial I for rotatation.

If now no further vehicle actuation occurs on either street, the'brakecoil-circuit is" not reclosed near the end of C street-green intervalbythe clial key' 24, because the recall switch 56 and the "extensionrelay-contacts 19 are both open. ihe

through the recall switch 65.

If, of course, within the predetermined exten- SiOn interval (i. e., 5seconds) prior to the closing coil circuit are both open the extensioninterval timing relays Ella and of the dial contacts 24a near the end ofthe C street green interval, a second vehicle actuation is registered onC street, the extension relay contacts 19 in the brake coil circuit of 2are held closed for one full extension interval, so that the dial key26', by closure of the dial contacts Za, does complete a brake coilcircuit during the C street green interval. This circuit is through theextension relay contacts l9 and the maximum timing relay contacts 8!.additional extensions, if registered prior to the expiration of theprevious extension, will be effective in maintaining this brake coilcircuit until such time as the C street maximum timing relay 82 opensits contact 8! in the brake coil circuit.

Either at this time or simply upon expiration of the last extension callthe timing dial I l will again be set in operation Without any vehicleactuation on M street by reason of the fact that either the contacts :5or the contacts 51 and the recall switch 65 in the brake coil circuitare open. Thus the recall switch 66, being in series with the memoryrelay contacts 83, function to simulate a permanent call on M street.

It should also be noted that, with the apparatus set for normal returnto M street green as described above, extension on the M street greeninterval may be obtained within the M street maximum interval. That is,if with the timing dial M at rest on the key 23 near the end of the Mstreet green dial interval, a vehicle actuation is registered on Mstreet and the M street maximum right-of-Way interval has not expired,the M street maximum timing contacts '55 (Fig. 2)

:will still be closed and the M street extension contacts '53 will beclosed for an extension interval in response to the vehicle actuation.Thus, the braking circuit through the M street dial contacts 23a ispositively maintained for the extension interval even though a vehicleactuation on C street effects an opening of the memory relay contactsll. Such M street extensions may continue to be registered until thetermination of the M street maximum right-of-way interval.

Fully actuated-With automatic return to cross street right-of-way Theapparatus may be set for full actuation with automatic return to Cstreet green by closing the recall switch 55 and leaving the recallswitch 65 open. The operation under this condition of the apparatus isentirely similar in all respects to that described above in connectionwith automatic return to M street green.

Pretz'med operation with vehicle extenszons on both streets apparatus isalso operable as a normally pretimed apparatus providing for timeextension in response to vehicle actuation on both streets. For suchoperation both the recall switches 65 and 56 are left open. Under thesecircumstances, and in the absence of any vehicle actuation, theextension relay contacts l3 and 79 in th brake at all times because llSaare maintained picked-up and thus retain the interval extension relays7-; and 8d picked-up. Therefore, with the recall switches 5 and iii?open, no brake coil circuit is ever completed upon closure of the dialcontacts 23a or B la. Thus the motor l5 continues in operation and thetiming dial It rotates continuously.

It will be noted, however, that at the beginning of each right-of-wayinterval, either on M or C Similarly,

76 for the locking relay Hit.

street, timing of a maximum right-oi-way interval for the street gettingthe green signal is initiated by closure of either the drum contacts 49or the drum contacts 59. Thus, if it is assumed that in continuousoperation the timing dial M has just initiated a C street greeninterval, the drum contacts 49 will be closed, thereby to initiate atiming interval for the maximum timing relay 82. The relay 32 will thusremain dropped out for the maximum time interval and will hold itscontacts 8! in the brake coil circuit closed. If now Within oneextension interval (i. e., 5 seconds) prior to closure of the dialcontacts 24a near the end of the C street green interval, a vehicleactuation is registered on 0 street, the detector relay contacts 95 willbe opened and reclosed to initiate a timing interval for the extensioninterval timing relay ll3a. The relay 5 53a will thus remain dropped outand will maintain the interval extension relay 8E! dropped out for thefull extension interval. When, during this interval, the dial contacts24a are closed by the key 24 near the end of the C street green dialinterval, a brake coil circuit is completed, so that the timing dial itis held stationary on the dial key 24. If only one extension isregistered, the dial is will again be set in operation at the end of theextension interval when the extension relay contacts i9 open. If,however, further extensions are registered prior to expiration of thepreceeding extension and also prior to expiration of the maximumright-ofway interval timed by the relay 82, the timing dial will befurther held up, either until the expiration of the last extensioncalled or until the expiration of the maximum interval, as describedhereinbeiore.

Similar time extensions may be registered on M street during the Mstreet green interval by operation of the dial contacts 23a inconjunction with the extension relay contacts 73 and the maximum timingrelay contacts 15.

Looking relay circuits with a call or simulated call registered on theother street. Specifically let it be assumed that the timing dial hasjust moved off of the brake coil key 23 at the end of M street green onthe timin dial. If now, between the opening of the dial contacts 23a andthe end of the M street reen interval as determined by the nearest dialkey 2i, a vehicle actuation is registered on M street, an extension willnot be obtained by the actuating vehicle because of the prior opening ofthe dial contacts 23a, and the vehicle will not have time to cross theintersection. Moreover, during this short interval the drum contacts 48are open so that the detector relay 88 will not pick-up the memory relay84.

However, the detector relay as, in response to the vehicle actuation,has dropped out the extension timing relay 1 i la, so that the intervalextension relay is! will remain dropped out for one extension interval.The extension relay M will therefore close its contacts E8511 in thememory relay circuit (Fig. 6). Also, during the amber interval followingthe termination of the M street green interval the drum contacts 58 areclosed, thereby to complete an energized circuit When the locking relaybeing no main tensions and maximum contacts 1?! and 8!.

i l p p t, eS itsncrm lly one i n aei i525,- thereby: to complete anenergizing circuitfor the, actuating. winding Hi3 of the memory relayThis energizing circuitincludes the drum contacts which are open onlyduring the M streetgreen interval and are thus closed during the amberinterval follow ng M street green. The memcry'relaytt, whenenergizedlocks itself in through its, interlock contacts I8 5, and-therebyremembers the call from the late arriving vehicle on M street. Thus thememory relay B t retains its contacts 83 and the brake coil circuitopenuntil; the exp ration of all extensionscalled on C street, whereupon therake coil circuit is interrupted and. the timing dial Mresumes itsoperation" to retransfer the right-oi-way back to M street in response,to the call of the late arriving vehicle.

An entirely similar locking operation takes place in conjunction withthe looking relay it: upon actuation of the cross street detector undercircumstances similar to those described im1ne- .diately above for themain street.

From the foregoing it will be understood that if a vehicle" on eitherstreet actuates a detector during the amber interval following aright-of- Way interval {the memory relay for that street picks-updirectly through the delector relay contacts 95 or 93, since theappropriate drumcontactsz'il or '48 are then closed. The memory relaysremember such calls in the same manner as describedabove, but withoutthe use or need o'i'tlie locking relays.

Pa tial actu io vehicle detectors are supplied only on one of theintersecting streets. If, for example, it is assumed that only crossstreet actuation is desired, the discharge'devices ME: and MM providingfor main street extensionand maximum timing are omitted, along with theomission of the timing relays i i la and H5, the interval'extensionrelay M, the locking relay H35 and the memory relay 36,. Thus,referringto Fig; 2, the brake coil circuit is normally closed,'in theabsence of any vehicle actuation, through the cross street memory relaycontacts 'ii. Cross street actuation "therefore will set the dialltl'iiito operation. There 'eirten'sicn and maximum contacts'l'f and '55being omitted, there can, of course, be no main street extensionregistered. However, when the dial contactsZ-ia are closed near the endof the cross street green intervaL'cross street extensions may beobtained through the cross street ex- The diali'ld cannot of course beheld up on the dial 2d beyond the cross street maximum interval,

for the memory relay contact 33 is omitted and "the circuit permanentlyopen at this point.

Qneratioma i tersectiqnsci mor tha t tmfiio lanes Assume a three-wayintersection composed of streets A, B and C, with a controller built accordingto, the invention and arranged for automatie recall to'A; street.The rotating timer will thus normally be held stationary on alorake coilke'y positioned near the end of A street green. ,Ihave described'aboveamain street system in which anactuation 01 a cross street will releasethetimer. fora sin r o u ion- I is ew a street detector; and the mainstreet 7 sumed thati erel -r etw s c crossfi r e tsseh having a:detector, sothat actuation oi either detector will release thetimer fora singlerevolue tion; Such a modification, requires only a du p licationof parts, and-isnot significantly different from the single cross streetembodirrientillustrated, which is provided with two detectors, one for;each direction of movement, and either of which will release thetimerforone completerevolution.

Assuming thena three. street intersection with the timernormallystationary on A street green and detectors in each orthe threestreets,itJis evident that an actuation of either the. Bstreet detector or the Cstreet detector-will initiate one revolution of the timing dial.Operation under these circumstances is clear from the. foregoingdescription or" main street recall operation.

Suppose, for example, that the B street detector is first actuatedand-thenthe C strfectQdetector; is actuatedshortly; thereafter.Actuation of the B street detector willstart a single timing cycle byreleasing the timer. Such a cycle will include a period-at C streetgreen, whichjgives the rightof-w ay in due. course to the car on Cstreet. If the actuation onC street came sosoon after the B streetactuation that 13 street green had not yet arrived, theC streetactuation is simply superfluous. If the C street actuation came duringthe 0' street green interval, and suiffie ciently near the end of the Cstreet green iriterval, the timer would be. stopped momentarily on the,0 street green position to grant an extension for the C street can Suchanextensionof. the green interval duringa; rotation of the timer isdescribed above. Finally, lithe actuation on .0 street came aiter theCstreet green intervalgor so late in the, C street green intervalthat itwas ineffective toobtain anextension of C street green, then the memoryrelay will remain actuated and initiate another cycle of operationafterthe first cycle is completed.

Carrying the assurned example still further, if the reverse condition isstill true, so that a first actuation comes on C street and shorlythereafter an actuation occnrs'on B street, the first actuation (Cstreet) will initiate one revolution of the timing dial. During thiscycle of operation, 3 street will get the green 'lightbefore .0 street,so that anycar arriving on; B street very shortlyafter that on C streetwill get the right of way. If the B street car arrived during, theBstreet green interval, it would simply registera B street greenextensionautomatically, as described above. Ii on theother hand the caron the B street arrived after the 3 street green interval, or so nearthe end of the B street green interval that it was unable to obtain anextension, the memory relay would remember the actuation and initiateanother cycle of operation in the manner heretoforedescribed.

Thus, by a mere duplication of parts, it is clearly possibletoextend-the application of my invention to a three street, fourstree't orfive street intersection, or to any desirednumber of interaaoa'scs careof more "thana single pair of intersecting traific lanes is obvious. Asimple paralleling of additional contacts, relays, -etc., is all that isrequired.

It Will now be evident from the foregoing description that my new'andnovel vehicle actuated trafiic signal control-system and apparatus isextremely flexible in providing simple adjustment for operation in anyone of a number of Ways. It has a further advantage in providing amaximum of continuity 'or" service, for the timing unit I2 shown at Fig.13 may easily be detached from the apparatus at the plug connector 52aand the apparatus readily set for temporary pretimed operation simply byopeningboth recall switches 65 and 66. In such temporary operation withthe timing unit I2 disconnected, of course, simple pretimed operation isobtained. No right-of-Way extensions are possible in response 'tovehicle actua'tion because the t' and i i 30: are removedfromthecircuit.

While I have described by way of illustration only a preferredembodiment of my invention, many modifications \vill'oc'cur to thoseskilled in the art, and I therefore wish to have it understood that Iintend in the appended claims to coverall such modifications-as fallwithin' the true spirit and scope o'fimy invention.

What I claim as new and desire to secure by Letters Patent .inthe:United States is:

1. .Avehicle' actuatedtrafiic signal control systern comprising a signal:device providing stop and go indications 'for each of a pluralityofintersecting trafiic lanes, a rotatable signal ;program controllerhaving anelectric driving motor, electric bra-king means for said motor,means for energizing said braking means in at least one of a piuralityof predetermined controller positions corresponding to alternateconditions of signal indication, and means actuated byavehicle-approaching said device for disabling said braking means therebyto release .said vcontroller .for operation to alternate said signalindication.

A vehicle actuated ,tramc signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting trafnc lanes, a, rotatable signal program controller havingan electric driving motor, electric braking means for saidmotor, meansfor energizing said braking meansin any of aplurality of predeterminedcontroller positions corresponding to alternate conditions of signalindication, and means actuated by a vehicle approaching said devicecn-a'lane having a stop indication for disabling said'braking means,there-- by to release said controller for operation to a subsequentcontroller position in which a go indication appear on said'lan'e. k

A vehicle actuated traific signal control system comprising a signaldevice providing stop and go indications for each cf'a plurality ofintersecting'traflic "lanes, a rotatable signalprogram controiler havingan electric driving motor, electricbra'king means i or 'said motorarranged when energized to hold said motor at rest, means 'forenergizing said-braking means only in any of a plurality ofpredetermined controller position 'corresponding'to predeterminedconditions-of signal indication, means actuated by a vehicle approachingsaid device one street having a stop indication for disabiingsaid'bra'king means thereby to release said col-itro'ller for operation,said controller when released preventing r'eenergization of said hrakingmeans at least until said signal deviceindicat'es go"to*sai'd veli'icle.

ng'relays hi, 82, "Illa 4. A vehicle actuated trafiic signal controlsystem for a pair of intersecting trafiic lanes comprising a signal device providing stop and go indications for each of said lanes, arotatable signal program controller including an electric driving motorhaving a braking coil, means responsive to controller position fornormally energizing said braking coil in a controller position whereinsaid signal device displays a stop indication to a minor lane and a goindication to a major lane, means including a detector actuable by avehicle ap roaching said device on said minor lane for disabling saidbraking coil thereby to release said controller for a complete cycle ofoperation to alternate said signal indications.

5. A vehicle actuated trafiic signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting trafiic lar s, a rotatable signal program controller incl:Zing an electric driving motor having opposed running and brakingwindings, said braking winding when energized holding said motor in aposition of rest, means inc lding a contact actuated by said controllerfor Zing braking winding in either of two controller positionscorresponding to alternate conditions of signal indication, and meansresponsive to approach of a vehicle on a lane having a stop indicationfor deenergizing said braking winding, thereby to release saidcontroller for operation to change said signal indication.

6. A vehicle actuated trafilc signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting trafiic lanes, a rotatable signal program controllerincluding an electric driving motor having opposed running and brakingwindings, said braking winding when energized holdsaid motor in aposition of rest, means inclu .ing a contact actuated by said controllerfor energizin said braking winding in either of two controller positionscorresponding to alternate conditions of signal indication, meansresponsive to approach of a vehicle on a lane having a stop indicationfor deenergizing said braking winding thereby to release said controllerfor operation to change said signal indication, and means responsive toapproach of a vehicle on a lane having a go indication for preventingfor a predetermined interval said deenergization of said braking windingby a vehicle approaching a stop indication.

7. A vehicle actuated trafiic signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting trafilc lanes, a rotatable signal ,program controllerhaving an electricdriving motor, elec 'ic braking means for said motor,means for energizing said braking means in any of a plurality ofpredetermined controller positions corresponding to alternate conditionsof signal indication, ineans actuated by a'vehicle approaching saiddevice on a lane having a stop indication for disabling said brakingmeans thereby to release said controller for operation to alterhate thesignal indication, and means actuated by a vehicle approaching saiddevice on a lane having a go indication for preventing for apredetermined interval disabling of said braking means.

8. A vehicle actuated traffic signal control system comprising a signaldevice providing stop and go indications icr each of a plurality ofintersecting trafiic lanes, a rotatable signal program controller havingan electric driving motor, electric braking means for said motor, meansfor energizing said braking means in a controller osition correspondingto a predetermined dition of signal indication wherein a go signal isdisplayed to one of said lanes and a stop signal is displayed to anotherof said lanes, means actuated by a vehicle approaching said device on alane having a stop indication for disablin said braking means thereby torelease said controller for operation to alternate the signalindication, and means actuated by a vehicle approaching said device on alane having a go indication for rendering said disabling meansineffective for a predetermined interval thereafter.

9. A vehicle actuated traffic signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting traffic lanes, a rotatable signal program controller havingan electric driving motor, electric braking means for saidmotor, meansfor energizing said braking means in at least one of a plurality ofpredetermined controller positions corresponding to alternate conditionsof signal indication, means actuated by a vehicle approaching saiddevice on a lane having a stop indication for disabling said brakingmeans thereby to release said controller for operation to alternate saidsignal indication, means actuated by vehicles approaching said device ona lane having a go indication for rendering said disabling meansineffective for a predetermined interval following the last of suchactuations thereby to extend said go indication, and time element meansfor limiting said extension to a predetermined maximum permissibleduration.

10. A vehicle actuated traffic signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting traflic lanes, a rotatable signal program controller havingan electric driving motor, electric braking means for said motor, meansfor energizing said braking means in at least one of a plurality ofpredetermined controller positions corresponding to alternate conditionsof signal indication, means actuated by a vehicle approaching saiddevice on a lane having a stop indication for disabling said brakingmeans thereby to release said controller for operation to alternate thesignal indication, means actuated by each vehicle approaching saiddevice on a lane having a go indication for rendering said disablingmeans ineiiective for a predetermined interval following each saidactuation thereby to extend said go indication, and time element meansactuated by said controller for limiting the maximum permissibleduration of said extension.

11. A vehicle actuated trafilc signal control system comprising a signaldevice providing stop and go indications for a plurality of intersectingtraific lanes, a rotatable signal program controller including anelectric driving motor having opposed running and braking windings, saidbraking winding when energized holding said motor in a position of rest,means including a contact actuated by said controller for establishingan energizing circuit for said braking winding in at least one of aplurality of controller positions corresponding to alternate conditionsof signal indication, means actuated by a vehicle appreaching saiddevice on a lane having a stop indication for interrupting said brakingcircuit thereby to release said controller for operation to alternatethe signal indication, means actuated displays a stop indication to byeach vehicle approaching said device on a lane having a go indicationfor rendering said interrupting means ineffective for a predeterminedinterval following each of such actuation thereby to extend said goindication, and time element means actuated by said controller forrestoring the effectiveness of said interrupting means after an intervalgreater than said predetermined interval.

12. A vehicle actuated traflic signal control system comprising a signaldevice providing stop and go indications for each of a plurality ofintersecting traffic lanes, a rotatable signal program controller havingan electric driving motor, electric braking means for said motor, meansresponsive to controller position for normally energizing said brakingmeans in a controller position wherein said signal device displays astop indication to a minor lane and a go indication to a major lane,means including a detector actuable by a vehicle approaching said deviceon said minor lane for disabling said braking means thereby to releasesaid controller to alternate said signal indication, means responsive toactuation of said detector by vehicles approaching said device on saidminor lane against a go indication for energizing said braking meansthereby to extend said go indication, and time element means actuated bysaid controller upon initiation of a go indication on said minor lanefor independently disabling said braking means after a predeterminedmaximum extension interval.

13. A vehicle actuated traffic signal control system comprising a signaldevice providing stop and go indications for a pair of intersectingtraiiic lanes, a rotatable program controller having an electric drivingmotor, electric braking means for said motor, means responsive tocontroller position for normally energizing said braking means at a,controller position wherein said signal device displays a stopindication to a minor lane and a go indication to a major lane, meansincluding a detector actuable by a vehicle approaching said device onsaid minor lane for disabling said braking means thereby to release saidcontroller for operation to alternate said signal indication, meansincluding a second detector actuable by a vehicle approaching saiddevice on said major lane with said controller in said normal positionfor rendering said disabling means ineffective for a predeterminedinterval following such major lane actuation, and time element meansactuated by said controller upon initiation of a major lane goindication for rendering said second detector means inefiective after amaximum interval greater than said predetermined interval.

14. A vehicle actuated trafiic signal control system for a pair ofintersecting trafiic lanes comprising a signal device providing stop andgo indications for each of said lanes, a rotatable signal programcontroller having an electric driving motor, means responsive tocontroller position for normally disabling said motor in a controllerposition wherein said signal device a minor lane and a go indication toa major lane, means including .a detector actuable by a vehicleapproaching said device on said minor lane for rendering said disablingmeans ineffective thereby to initiate a complete cycle of controlleroperation, and means responsive to actuation of said detector while thego indication is displayed to said minor lane for delaying saidcontroller for at least a predetermined interval at a position tocontinue the go indication on said minor lane.

15. A vehicle actuated trafiio signal control system for a pair ofintersecting traffic lanes comprising a signal device providing stop andgo indications for each of said lanes, a rotatable signal programcontroller having an electric driving motor, means responsive tocontroller position for normally disabling said motor in a controllerposition wherein aid signal device displays a stop indication to a minorlane and a go indication to a major lane, means including a detectoractuable by a vehicle approaching said device on said minor lane forrendering said disabling means inefiective thereby to initiate acomplete cycle of controller operation, and means responsive tosubsequent vehicle actuation of said detector while the go indication isdisplayed to said minor lane for disabling said motor for at least apredetermined interval in a controller position to extend said minorlane go indication for said predetermined interval.

16. A vehicle actuated trams signal control system for a pair ofintersecting trafiic lanes of relatively minor and major dignitycomprising a signal devic providing stop and go indications for each ofsaid lanes, a rotatable signal program controller having an electricdriving motor, means responsive to controller p sition for normallydisabling said motor in a controller position wherein said signal devicedisplays a stop indication to said minor-lane and a go indication tosaid major lane, means including a detector actuable by'a vehicleapproaching said device on said minor lane for rendering said disablingmeans ineffective thereby to initiat operation of said controller'totransfer the go indication to said minor lane, and means including adetector actuable by a vehicle approaching said device on said majorlane while said controller is at rest in said normal position formaintaining said motor disabled for at least a predetermined in tervalthereafter independently of detector actuations on said minor lane.

17. A vehicle actuated trafiic signal control system comprising a signaldevice providing with stop and go indications for each of a plurality ofintersecting traflio lanes, a rotatable signal program. controllerhaving an electric driving motor, electric braking means for said motor,

means responsive to controller position for cornpleting an energizingcircuit for said braking means in any of a plurality of predeterminedcontroller positions corresponding to alternate conditions of signalindication, means actuated by a vehicle approaching said device on alane having a stop indication for interrupting said energiz ng circuitthereby to release said controller for operation to the next consecutiveposition to alternate said signal indication, and means actuated byvehicles approaching said device on a lane having a go indication forrendering said interrupting means ineffective for a predeterminedinterval following each such actuation thereby to extend said goindication.

18. A vehicle actuated trafiic signal control system comprising a signaldevice providing stop and go indications for each or" a plurality ofintersecting trafiic lanes, a rotatable signal program controller havingan lectric driving motor, electric braking means for said motor, meansresponsive to controller position for completing an energizing circuitfor said braking means in any of a plurality of predetermined controllerpositions corresponding to alternate conditions of fit 22 signalindication, meansactuated by a vehicle approaching said device on a lanehaving a stop indication for interrupting said energizing circuitthereby to release said controller for operation to the next consecutivepredetermined position to alternate said signal indication, time elementmeans actuated by vehicles approaching said device on a lane having a goindication for rendering said interrupting means ineffective for apredetermined interval following each such actuation, said time elementmeans being eiiective to extend said go indication only if actuated whensaid controller is at rest or within said predetermined interval beforesaid controller comes to rest.

19. A vehicle actuated traffic signal control system comprising a signaldevice providing a stop and go indication for each of a plurality ofintersecting trafiic lanes. a rotatable signal program controller havingan electric driving motor, electric braking means for said motor, meansresponsive to controller position for completing an energizing circuitfor said braking means in any of a plurality of predetermined controllerpositions corresponding to alternate conditions of signal indication,detector means actuated by a vehicle approaching said device on a lanehaving a stop indication for interrupting said energizing circuitthereby to release said controller for operation to the next consecutiverest position to alternate said signal indication, second detector meansactuated by vehicles approaching said device on a lane having a goindication for rend ing said disabling means ineilective for a pro otermined interval following each actuation 0 said second detector meansthereby to extend go indication, and time element means actuated by saidcontroller upon initiation of a go indication on any lane for restoringthe eiiectiveness of said interrupting means after a predeterminedmaximum permissible right of way interval.

20. A traffic control system comprising a signal device providing stopand go indications for each of a plurality of intersecting traihc lanes,a rotatable signal program controller having an electric driving motor,means normally connecting said motor for continuous rotation therebycontinuously to alternate said signal indications, electric brakingmeans for said motor, and time element means responsive to approach of avehicle on a lane having a go indication for energizing said brakingmeans for a predetermined interval thereby to extend said go indication.

21. A traffic signal control system comprising a signal device providingstop and go indications for each of a plurality of intersecting trafficlanes,

a rotatable signal program controller having an eleotricdriving motor;means normally energizing said motor for continuous rotation therebycontinuously to alternate said signals in a pretimed interval sequence,and time element means responsive to approach of a vehicle on a lanehaving a go indication and within a predetermined interval before thenormal expiration of said go indication for energizing said brakingmeans for said predetermined interval thereby to extend said goindication.

A trafiic signal control system comprising a signal device providingstop and go indications for a plurality of intersecting trarfic lanes, arotatable signal program controller having an electric driving motor,means normally energizing said electric driving motor for continuousrotation thereby continuously to alternate said signals in a pretimedinterval sequence, electric braking means for holding said controller atrest,

time element means operable within a predetermined interval prior to thenormal expiration of a go interval and in response to the approach of avehicle on a lane having a go indication for energizing said brakingmeans for said predetermined interval following the approach of suchvehicle thereby to extend said go interval, and means including saidtime element means operable in response to the approach of successivevehicles on said lane and within said predetermined interval or whilesaid controller is at rest for maintaining the energization of saidbraking means for said predetermined interval following each suchsuccessive actuation thereby further to extend said go interval.

23. A traffic signal control system comprising a signal device providingstop and go indications for a plurality of intersecting trafiic lanes, arotatable signal program controller having an electric driving motor,means normaily energizing said driving motor for continuous rotationthereby continuously to alternate said signals in a pretimed intervalsequence, electric braking means for said motor, time element meansoperable in response to approach of vehicles on a lane having a goindication and within a predetermined interval prior to the normalexpiration of said go indication for energizing and successivelymaintaining the energization of said braking means for one saidpredetermined interval following each such actuation.

24. A traffic signal control system comprising a signal device providingstop and go indications for each of a plurality of intersecting trafficlanes, a rotatable signal program controller having an electric drivingmotor, means normally energizing said electric driving motor forcontinuous rotation thereby continuously to alternate said signals in anormal pretimed sequence, electric braking means for said motor, timeelement means operable in response to approach of vehicles on a lanehaving a go indication and within a predetermined interval prior tonormal expiration of said go indication for energizing and successivelymaintaining the energization of said braking means for one saidpredetermined interval following each such actuation, and second timeelement means for positively rendering said braking means ineffectiveafter a predetermined maximum permissible right-of-way intervalfollowing initiation of said go indication.

25. A vehicle actuated traffic signal control apparatus comprising asignal device providing stop and go indications for each of a pluralityof intersecting trafiic lanes, a rotatable signal program controllerhaving an electric driving motor, electric braking means for said motor,

means for establishing an energizing circuit for said braking means, andmeans responsive to vehicles approaching said device for controllingsaid energizing circuit.

2-6. A vehicle actuated trafl'ic signal control apparatus comprising asignal device providing stop and go indications for each of a pluralityof intersecting trafiic lanes, a rotatable signal program controllerhaving an electric driving motor, electric braking means for said motor,means establishing an energizing circuit for said braking means,detector means actuable in response to the approach of vehicles on atleast one of said lanes, and time element means actuated by saiddetector means for controlling said energizing circuit.

27'. A vehicle actuated traflic signal control apparatus comprising asignal device providing stop and go indications for each of a pluralityof intersecting traific lanes, a rotatable signal program controllerhaving an electric driving motor, electric braking means for said motor,detector means substantially instantaneously responsive to the approachof a vehicle on at least one of said lanes, means including saiddetector means for establishing an energizing circuit for said brakingmeans, and time element means responsive to actuation of said detectormeans for controlling said braking circuit.

28 A vehicle actuated trafiic signal control apparatus comprising asignal device providing stop and go indications for each of a pluralityof intersecting trafiic lanes, a rotatable signal program controllerhaving an electric driving motor, electric braking means for said motor,

means normally establishing an energizing circuit for said brakingmeans, detector means operable in response to the approach of vehicle onat least one of said lanes for interrupting said braking circuit, timeelement means controlled by said detector means for controlling saidenergizing circuit, and means for disconnecting said time element meansand simultaneously disabling said braking circuit independently of saiddetector means, thereby to provide for temporary continuous rotation ofsaid motor and pretimed operation of said controller.

VINCENT W. LEONARD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,973,563 Friendly Sept. 11, 19342,122,410 Eames July 5, 1938

